the Black King's movements to as few squares as possible.
We might now continue: 3...K - Kt 2; 4 K - B 2. In this ending the Black King must not only be driven to the edge of the board, but he must also be forced into a corner, and, before a mate can be given, the White King must be brought to the sixth rank and, at the same time, in one of the last two files; in this case either K R 6, K Kt 6, K B 7, K B 8, and as K R 6 and K Kt 6 are the nearest squares, it is to either of these squares that the King ought to go. 4...K - B 2; 5 K - Kt 3, K - Kt 2; 6 K - R 4, K - B 2; 7 K - R 5, K - Kt 2; 8 B - Kt 6, K - Kt 1; 9 K - R 6, K - B 1. White must now mark time and move one of the Bishops, so as to force the Black King to go back; 10 B - R 5, K - Kt 1; 11 B - K 7, K - R 1. Now the White Bishop must take up a position from which it can give check next move along the White diagonal, when the Black King moves back to Kt 1. 12 B - K Kt 4, K - Kt 1; 13 B - K 6 ch, K - R 1; 14 B - B 6 mate.
It has taken fourteen moves to force the mate and, in any position, it should be done in under thirty.
In all endings of this kind, care must be taken not to drift into a stale mate.
In this particular ending one should remember that the King must not only be driven to the edge of the board, but also into a corner. In all such endings, however, it is immaterial whether the King is forced
